chrome.runtime.onMessage.addListener(function(request,sender,sendResponse){
    let doms=document.getElementsByClassName("KL4Bh");
    if(doms!=null){
        for(let i=0;i<doms.length;i++){
            let srcset=doms[i].children[0].srcset;
            if(srcset!=undefined){
                let list=srcset.split(",");
                for(let x=0;x<list.length;x++){
                    let li=list[x].split(" ");
                    if(li[0]===request.url){
                        sendResponse({result:doms[i].children[0].src});
                        return
                    }
                }
            }else{
                sendResponse({result:"nil"});
                return
            }
        }
    }else{
        sendResponse({result:"nil"})
    }
});
